The present invention relates to an automated system and a process for repairing components such as turbine vanes.
Components in gas turbine engines are exposed to high temperatures and pressures for extended periods of time. A typical application is high pressure turbine vanes where the temperature of the component can rise to well over 2000xc2x0 F. Under these conditions, the component is expected to retain its strength and shape long enough to provide economical operation of the engine without unduly frequent service or replacement requirements.
After extended service, some components incur damage due to erosion and fatigue-induced cracking. Eventually, these components need to be repaired or overhauled.
During overhaul, it is necessary to apply a pasty braze repair material over the airfoil surfaces and the platforms of the component to fill any cracks and all of the cooling holes that may be present in the component. Thereafter, the component is placed in a furnace to complete the brazing operation. Typically, there is excessive repair material left on the surfaces of the component, which repair material has to be removed and/or manually blended to return the component as close as possible to its original shape. The brazing materials used in this process have a high hardness, i.e. Rc 50 or greater, and very low machinability. Consequently, manual blending takes a long time to completexe2x80x94an average of 60 to 75 minutes per vane. Only very skilled operators can do the manual blending consistently as the complex airfoil shape is blended back blindly as many surfaces are covered with the repair material. Further, the shape obtained is not accurate because of the limits of the manual operation.
The challenge here is that unlike normal part making where the component geometry is known and hence a constant blend path can be generated, here the repair component geometry changes from component to component. This is because the component has been in service on an engine for a long time in a high temperature environment. Due to the severe operating conditions, the components coming for overhaul or repair are normally distorted. This means that existing CAD geometry data cannot be used to create a standard blend path to blend all the components. The additional challenge here is that the outside airfoil geometry has to be blended consistent with the inside hollow geometry to maintain a designed amount of metal thickness because both the inside and the outside profiles are distorted by operating conditions. The repaired coated surface offers few original virgin surfaces for reference or tooling.
Accordingly, it is an object of the present invention to provide a system and a process for repairing components.
It is a further object of the present invention to provide a system and a process as above which reduces process time and labor cost.
It is still a further object of the present invention to provide a system and a process as above which produces a repaired component with enhanced quality.
It is yet a further object of the present invention to provide a system and a process as above in which the airfoil profile of the component is closer to the required form.
The foregoing objects are attained by the system and the process of the present invention.
In accordance with the present invention, a system for repairing a component is provided. The system broadly comprises means for generating instructions for performing an operation to remove any excess repair material from each surface of a component being repaired and to blend the repaired surfaces, and automated means for performing the blending operation in accordance with the generated instructions. The system further includes means for generating an image of each component surface having repair material thereon which requires removal and/or blending.
Further in accordance with the present invention, a process for repairing a component is provided. The process broadly comprises the steps of generating instructions for performing an operation to remove excess repair material from each surface of the component being repaired and to blend the repaired surfaces and performing the blending operation in accordance with the generated instructions.
Other details of the system and the process of the present invention, as well as other objects and advantages attendant thereto, are set forth in the following detailed description and the accompanying drawings, wherein like reference numerals depict like elements.